Mark Deeks off of Countdown did a nice one on Facebook earlier that at least Jim, Ian and myself are engaging with:

Mark wrote:
Inasmuch as genres don't matter and that perfection is a nebulous concept, what is the perfect song for each genre of music?

So, shall we try it? It's not exactly Games and Puzzles but Off-Topic is already the best subforum here so spreading the love.

I think we have to be restrained and agree that we should hold back from making suggestions of actual songs or even of the child-level subgenres yet.

My suggestion would be that we attempt to start with an agreement of all of what we could call the top-level genres. Got to structure this right if we're going to do it properly and this is as good a start as I can think of, though obviously I appreciate it has its problems:

Questions like "is metal a subgenre of rock or a top-level genre in itself?" - in this instance by the way I'm saying separate since there are so many recognised subgenres of metal that it warrants being top-level by virtue of the consistence of the "<subtype> <genre>" naming recognisable across global subgenres.

Some subgenres are going to straddle two (or more) top-level genres.

Electronic is absolutely fucking massive and we're likely to need to split it into separate top-level genres in order to avoid having nested subgenres (or are nested ok? - maybe they are?)

There's a lot of what you could roughly call 'experimental' or 'abstract' music in my collection - turntablism, noise, glitchy stuff - which I have no idea where to fit in. I nominate IDM as a top-level genre I think to help house at least some of this.

One I really struggle with - the age of stuff. How do we compare (and categorise) 70s pop with modern pop etc. ?

Not entirely dissimilarly, what about "world music"? Although there may be recognisable subgenres very specific to certain global regions, this term is also often used as just a reapplication of agreed genres/subgenres to exclusively foreign music, and how should we handle this?

Genres- 2018.05.09 status: still gathering top-level genres

Blues

Country

Classical

Electronic

Folk

Funk & Soul

Hip-Hop

Indie

Jazz

Latin

Metal

Pop

Reggae

Rock

For potentially useful reference, I also just found this list of top-levels on Discogs:
You can also see all the "styles" they use (their term where I've used subgenres) here, though it's more useful perhaps to view them by clicking "All" to expand the listing on the left of e.g. the homepage, as you can then see them in order of frequency. They have so many subgenres already organised, and you'd probably say would be a reliable resource to base this on, but we're never going to do 500 different subgenres, so where do we draw the line? Our knowledge? Our interests? Our willingness to say at some point "that's enough" and accept an awkward "All other music" category?

And for fun, here's a picture of what my top-level genres are at home:

Anyway, while Matt Morrison off of Apterous's obsessive compulsive disorder and love of linearity anchors what could have been a fun discussion with its turgid reliance on structure, let me reassert my authority by kicking things off with a link to the tune that catalysed the whole shaboodle, in direct circumvention of the Morrison Rules.

Like anything, hip-hop can be sub-categorised to death. It's for others to do so. Yet in terms of simple beat-driven, sample-driven, four-bar, before-he-got-caught-up-in-musical-theory hip-hop, for which Dre made his name and which remains the foundation of the genre, the magnetic majestic simplicity of this tune is pretty perfect. Obviously it starts with those keys, but all the little touches are so well done, and the drum line is the perfect balance of heavy, head-bobbing yet unintrusive.

Eoin Monaghan wrote:
He may not be liked on here, but you have to give some credit to Mark